Re: [GZG] Not So Small thought re: Orbital Assault

Orbital assaults:

I've been giving this a lot of thought, but from a rather different 
perspective.

First, working out what would be a good game, utilising as much as 
possible existing game mechanics, and only then coming up with the PSB 
to justify it, rather than looking at authenticity first, or what 
happened in Iraq, Normandy, Dnieperpetrovsk, Market/Garden, Gallipoli, 
Iwo Jima, Klendathu and Hoth. Or how much Fire Support Falkenberg's 42nd

or Hammers Slammers could call on.

Where I did examine both real and fictional invasions, I tended to 
concentrate on the more cinematic aspects : the "Commando" operations 
ideal for SGII, and the base assault on Hoth.

I started out with a "top down" approach : what planetary defences could

do, what their likely limitations were, how they could be integrated 
into the GZGverse for FT primarily.

The easiest method, and one with the least impact on the rules 
mechanics, is to have planetary defence bases being merely motionless 
ships on a planet. After all, if the Planetary Defence Unit (PDU) system

is on an airless asteroid, what difference is there between a PDU and a 
cruiser that's moored to it?

But when you get to "objects of significant interest", ie habitable 
planets with biospheres, hydrospheres, and atmospheres, the problem 
becomes different. Then, you have to consider interactions of weapons 
with the atmosphere. For this, taking FT only as canonical, we have 
specialised Ortillery, which has limited if any Anti-ship (AS) 
capability, but is vastly better at planetary attack.

To get a decent game, we need to have normal weaponry degraded a LOT to 
make Ortillery useful. We also need to have PDUs cheap enough so they 
should exist, but expensive enough so system ships (with no FTL) become 
useful if there are multiple points in a system to be defended.

A reasonable break-even point is 2 : if only a single point (planet 
etc), then use a PDU. If 2, then 2 PDUs or the same cost in System 
Ships. If 3+, System ships would be better. A better break even point is

3, if tugs are available.

So let's say that a PDU costs 1/3 as much as the equivalent ship, 
providing its built near an industrial base. This is not so much due to 
the cost of lofting to orbit, but the use of cheaper construction 
materials ( 100 metre thick Ferro-concrete vs 2cm of Unobtanium), the 
use of oceans or underground rivers as heat exchangers, or whatever PSB 
you like.

Now a reasonable "firing arc" for weapons is 1 arc, 60 degrees. 
Otherwise, I dunno, the thickness of the atmosphere gets in the way, 
whatever. Firing arcs SMs stay at 180 degrees, the things can "bunt" 
after a vertical launch. Similarly, a PDU can only be fired at by things

in that arc.

The upshot is that a planetary invasion has 2 possibilities: to land 
"outside the arc" of the defences, and face a month-long slog vs local 
guerilla forces and counter-attack to get to the place of interest, or 
to drop in the teeth of the defences and take its lumps on the way in, 
hopefully having supressed them with ortillery.

A little jiggling of the fighter rules would allow fighters to be both 
useful planetary defences, and useful planetary attackers, operating 
inside the atmosphere and so with weapons not degraded. More jiggling, 
and "commando launches" of fighter-size, but carrying sticks of special 
forces, could land by stealth and conduct raids to take out the Beam-10s

of Navarone.

Well-settled planets, with population centres on multiple continents, 
will have multiple PDUs, with no single "safe" landing site arc. But 
that invites defeat in detail, if equally distributed, each 60 degree 
arc has only 1/6 of the defences that it would have if it was all in one

place, to state the obvious.

A neat way of balancing costs is to make them proportional to the number

of sites being defended. An outer colony, with 1 continent settled, will

have 1 PDU per X points. An inner world, with 6 continents settled, will

have 6 PDU for the same price - simply because it has more industry 
that's closer. So worlds can be considered in a strategic game as having

values of 1-6, indicating approximate population factors. A size 1 world

has ~10,000, size 2 ~100,000, size 6 ~1,000,000,000.

How much do PDU's cost? Let's say 1/3 of the equivalent ship, and they 
also get unlimited single-row armour free ( and all but bypassed by 
specialised Ortillery). Non-damagable Screens too, if the atmosphere is 
thick (but targets get the same protection). Damage to this armour 
indicates damage to the environment, civilian casualties etc. Cities 
could be represented by "passenger spaces". Give the PDUs too much of a 
pasting, and you'll kill megapeople in the bunkers. Use too many 
non-specialised planetary attack weapons, like the dreaded KV "Mass 
Drivers" or Beams, and you conquer a radioactive or dust-covered 
hellhole. That's why you need ground forces, and have a reason for DS2 
and SG2 games.

As to the exact mechanisms of landing troops, interface with tactical 
rather than defence-suppression ortillery etc, I leave that to the 
GroPos. This view is strictly that of the Sky Marshall, charged with 
getting the troops dirtside. It covers the space battles where an 
invasion fleet must fight its way through a mix of FTL, System-ship and 
PDU defences to land its troops (or conduct some strategic bombardment 
or close blockade), and that only.

Zoe

-- 
Zoe & Carmel Brain
http://aebrain.blogspot.com
mailto:aebrain@webone.com.au
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